In transportation vehicles, especially on board of air vehicles such as aircraft or airplanes for example, apparatuses for the warming or heating of media, i.e. gaseous and/or liquid fluids, particularly water and/or air for example, are being increasingly employed for various different applications or uses. Moreover, apparatuses for the cooling of fluids are also being used. Such apparatuses, which are often electrically operated, can for example be boilers, through-flow heaters, chillers, cooling devices, etc., in which water, for example, is tempered. The warmed or heated water or the produced steam can then be used, for example in on-board galleys for the preparation of hot beverages, meals and/or for cleaning or rinsing purposes. In sanitary areas, the warm or hot water can be used, for example, for water tap or faucet locations, bidets, bathtubs, showers, or the like. Cooled air or cooled water can be used, among other things, for the air conditioning of the cabin space within the vehicle.
The operation of these conventionally known electrical devices for the heating or cooling of larger water quantities is generally associated with a high demand of electrical energy. This pertains especially when sufficient warm or hot water is to be provided for showering or bathing. Rapid temperature changes in response to user requirements still further increase the energy demand necessary for the tempering of the fluid.
This leads to very high load peaks in the electrical on-board power supply of the transportation vehicle, e.g. an aircraft, especially in the time periods in which a high demand for warm and hot water exists, for example at the meal times or in the early morning after the sleeping phase of a flight. In order to be able to also cover the highest possible theoretically conceivable load peak in the electrical on-board power supply, it must be dimensioned correspondingly large. As a result, the electrical on-board power supply, including the conductor lines, the electrical generators, or the other current sources, must be laid-out or designed with a higher power capacity than would actually be necessitated by the average energy demand on board the transportation vehicle over the course of the entire day. The higher power capacity design of the electrical on-board power supply generally also necessitates a significant increase of the weight, which is disadvantageous especially in aircraft, because thereby the operating range is reduced, for example.
Thus, the conventionally known apparatuses that are exclusively electrically powered for the rapid tempering, that is to say for the warming, heating or cooling of larger volume flows of water and/or other fluids, are suitable only conditionally or with limitations, especially for air vehicles.